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Affected by global warming, the frequency of crop pests and diseases have increased, causing huge losses to agricultural production. To better grasp the development and trends of research on the effects of climate change on crop pests and diseases, the literature on the impact of climate change on crop pests and diseases published from 1990 to 2021 in the Web of Science (WOS) core collection database was used. This study explores the literature characteristics and hotspot evolution through the bibliometric visualization analysis software COOC, VOSviewer, and CiteSpace, with a view to identifying the changing characteristics and trends of research changes in this field. The results showed that the number of literature on the impact of climate change on crop pests and diseases increased rapidly. The main fields involved include environmental sciences, ecology, and agronomy. Papers in these fields mainly published in journals, such as PLos One, Forest Ecology and Management, and Frontiers in Plant Science. The country with the highest number of publications was the United States, followed by China and Australia. The most prolific authors in the top 20 are research scholars from China. The first author of the top 20 highly cited papers was from the United States. It was found that that current research on the impact of climate change on crop pests and diseases mainly focuses on agricultural production and food safety. Modelling and crop growth has maintained steady development. At present, research in this field mainly focuses on pest management strategies under the impact of climate change, the response of single species, and the complex ecological mechanisms behind the response. This study provides unique insights into the research field of the impact of climate change on crop pests and diseases and provides a reference direction for future research development in this field. [ABSTRACT FROM AUTHOR]

In order to figure out the impact of climate warming on crop planting areas, this paper used grid data to analyze agricultural heat resources in China based on methods of Sliding Mean Temperature of Five Days, accumulated anomaly, Manner- Kendall test and multiple regression interpolation. The results showed that: (1) The effective accumulative temperatures (⩾5 ° and ⩾10 ° ) show an overall upward trend, and the accumulative temperature of ⩾5 ° is more remarkable. The southern region has the highest inclination rate, followed by the northern region, and the Qinghai- Tibet Plateau has the smallest, while the cumulative temperatures of the Qinling- Daba mountains show a decreasing trend. (2) The effective accumulated temperatures (⩾5 ° and ⩾10 °) present a similar spatial distribution, namely, the accumulated temperature varied with latitude from south to north and varied with altitude from east to west. The eastern and central regions of China are obviously affected by latitude, while the western region is affected more by altitude than latitude. The area suitable for planting chimonophilous crop is larger than that suitable for thermophilic crop. (3) The effective accumulated temperatures of both ⩾5 ° and ⩾10 ° mutated in 1997, and both of their boundaries show a tendency toward northward and high altitude. The cumulative temperature increment in the south is larger than that in the north. The Qinghai-Tibet Plateau and mountain areas with high altitude have the smallest increase, while cumulative temperature increment is negative in the Qinling Mountains. (4) The initial days (closing day) of the effective accumulated temperature (⩾5 ° and ⩾10 °) presented an overall phenomenon of advance (delay), and the number of advance (delay) days is mostly within 0-10 days. Both of their durations increased overall after mutation. The number of initial days (closing day) in advance (delay) is the largest in the Qinghai-Tibet Plateau. [ABSTRACT FROM AUTHOR]

Complete and accurate global solar radiation (Rs) data at a specific region are crucial for regional climate assessment and crop growth modeling. The objective of this paper was to evaluate the capability of 12 solar radiation models based on meteorological data obtained from 21 meteorological stations in China. The results showed that the estimated and measured daily Rs had statistically significant correlations (P<0.01) for all the 12 models in 7 subzones of China. The Bahel model showed the best performance for daily Rs estimation among the sunshine-based models, with average R2 of 0.910, average RMSE of 2.306 MJ m−2 d−1, average RRMSE of 17.3%, average MAE of 1.724 MJ m−2 d−1, and average NS of 0.895, respectively. The Bristow-Campbell (BC) model showed the best performance among the temperature-based models, with average R2 of 0.710, average RMSE of 3.952 MJ m−2 d−1, average RRMSE of 29.5%, average MAE of 2.958 MJ m−2 d−1, and average NS of 0.696, respectively. On monthly scale, Ögelman model showed the best performance among the sunshine-based models, with average RE of 5.66%. The BC model showed the best performance among the temperature-based models, with average RE of 8.26%. Generally, the sunshine-based models were more accurate than the temperature-based models. Overall, the Bahel model is recommended to estimate daily Rs, Ögelman model is recommended to estimate monthly average daily Rs in China when the sunshine duration is available, and the BC model is recommended to estimate both daily Rs and monthly average daily Rs when only temperature data are available. [ABSTRACT FROM AUTHOR]

Based on compilation of a large number of archaeological and palaeosol 14C-ages, the Summed Probability Method is used to reconstruct population history and climatic patterns on the Chinese Loess Plateau during the period 8.5–3.5 cal. ka BP. During this period, the population experienced two major expansion periods and several climatic fluctuations. The first population expansion began at around 7.8 cal. ka BP, and the second at around 5.8 cal. ka BP. During the first period, although already in combination with cultivation of broomcorn millet the population growth was supported mainly by hunting and gathering. With the switch from broomcorn millet to foxtail millet, plant cultivation became the major factor promoting a second population increase. In this paper, we demonstrate that, initially, suitable climate and agriculture both can facilitate population growth and climate events had a significant influence on demographic fluctuations. However, when reaching the threshold of land capacity, population became increasingly more sensitive towards climate fluctuations. [ABSTRACT FROM AUTHOR]

Abstract: This paper assesses the impact of climate change on China''s agricultural production at a cross-provincial level using the Ricardian approach, incorporating a multilevel model with farm-level group data. The farm-level group data includes 13,379 farm households, across 316 villages, distributed in 31 provinces. The empirical results show that, firstly, the marginal effects and elasticities of net crop revenue per hectare with respect to climate factors indicated that the annual impact of temperature on net crop revenue per hectare was positive, and the effect of increased precipitation was negative when looking at the national totals; secondly, the total impact of simulated climate change scenarios on net crop revenues per hectare at a Chinese national total level, was an increase of between 79 USD per hectare and 207 USD per hectare for the 2050s, and an increase from 140 USD per hectare to 355 USD per hectare for the 2080s. As a result, climate change may create a potential advantage for the development of Chinese agriculture, rather than a risk, especially for agriculture in the provinces of the Northeast, Northwest and North regions. However, the increased precipitation can lead to a loss of net crop revenue per hectare, especially for the provinces of the Southwest, Northwest, North and Northeast regions. [Copyright &y& Elsevier]

Normalized Difference Vegetation Index (NDVI) is widely recognized as a good indicator of vegetation productivity. Diagnosing the NDVI trend and understanding climatic factors influences on NDVI can predict the productivity changes under different climatic scenarios. This paper examined NDVI dynamic and its response to climate factors during a 10 year period (1998-2008) in Inner Mongolia. The main findings are as follows: (1) The NDVI multi-scale characters can be revealed well by wavelet transform, and the average NDVI and the NDVI amplitude show a gradually decreased trend from northeast to southwest in Inner Mongolia during the past 10 years, furthermore, this trend is consistent with the heat and water distribution caused by latitude difference in north-south direction and Asia monsoon effect in east-west direction. (2) The relation between NDVI and temperature is the most close, followed by precipitation, sunshine hours and relative humidity. Different vegetation cover types show different strengths in correlation between NDVI and climate variables with the correlation values decreasing from forest, meadow steppe to desert steppe in whole. (3) The precipitation and temperature have the same change cycle, both nearly 290 days in the 20 selected stations. The NDVI has the same change cycle with the precipitation and temperature or either 10 days earlier or later than precipitation and temperature, which supports the significant correlation between NDVI and its climatic factors from a new perspective. The nearly 290 days change cycle implies that the vegetation growth cycle is nearly 10 months and there are no obvious differences change cycles in different vegetations. (4) Vegetation dynamic is significantly correlated to the temperature and precipitation at the time scale of 10, 20, 40, 80, 160, and 320-day, respectively, and the S3 scale (i.e., the time scale of 80-day), nearly 3 months (one season), is most significant and suitable for evaluating the vegetation dynamic to climatic factors. [ABSTRACT FROM AUTHOR]

Abstract: Crop reference evapotranspiration (ET 0) is often used to determine crop water requirement. ET 0 maps are useful for regional agricultural and water resources management, and also play an important role in the distributed hydrological modeling. For generating spatial ET 0 surfaces, ‘Interpolate-then-calculate (IC)’ approach is powerful in principle and is recommended especially for sparse weather station networks. The partial thin-plate smoothing spline incorporated in ANUSPLIN for interpolating climatic variables has been accepted widely across the world. In this paper, the climatology monthly ET 0 data of Shiyang river basin, one of the three inner basins in northwest China, are developed by spatially modeling the input climatic parameters with ANUSPLIN, and from the interpolated climate and ET 0 datasets, sensitivity coefficients of ET 0 to the climatic variables of selected months are also spatially distributed. In the cool months (January, February, November and December), the spatial variability of ET 0 is small and the value is rather low, whereas the warm season (May, June, July and August) is characterized by high values of ET 0 and large spatial variations in the river basin. Vapor pressure deficit is the most sensitive variable during the cool months and in the mountainous area with lower temperature; mean air temperature is the least sensitive one during the year and a little variation is observed at the basin scale. In summer, available energy primarily forces ET 0 as expected, and in winter, wind speed plays an important role and affects ET 0 greater at the northern plain region where deserts are dominated by dunes and low shrubs. We conclude that for regions with isolated climate stations, ‘IC’ procedure by including topographic and geographic factors can effectively model spatially distributed ET 0. [Copyright &y& Elsevier]

This paper explores changes in climatic variables, including solar radiation, rainfall, fraction of diffuse radiation (FDR) and temperature, during wheat season (October to May) and maize season (June to September) from 1961 to 2003 at four sites in the North China Plain (NCP), and then evaluates the effects of these changes on crop growth processes, productivity and water demand by using the Agricultural Production Systems Simulator. A significant decline in radiation and rainfall was detected during the 43 years, while both temperature and FDR exhibit an increasing trend in both wheat and maize seasons. The average trend of each climatic variable for each crop season from the four sites is that radiation decreased by 13.2 and 6.2 MJ m−2 a−1, precipitation decreased by 0.1 and 1.8 mm a−1, minimum temperature increased by 0.05 and 0.02°C a−1, maximum temperature increased by 0.03 and 0.01°C a−1, FDR increased by 0.21 and 0.38% a−1 during wheat and maize season, respectively. Simulated crop water demand and potential yield was significantly decreased because of the declining trend in solar radiation. On average, crop water demand was decreased by 2.3 mm a−1 for wheat and 1.8 mm a−1 for maize if changes in crop variety were not considered. Simulated potential crop yields under fully irrigated condition declined about 45.3 kg ha−1 a−1 for wheat and 51.4 kg ha−1 a−1 for maize at the northern sites, Beijing and Tianjin. They had no significant changes in the southern sites, Jinan and Zhengzhou. Irrigation, fertilization development and crop variety improvement are main factors to contribute to the increase in actual crop yield for the wheat–maize double cropping system, contrasted to the decline in the potential crop yield. Further research on how the improvement in crop varieties and management practices can counteract the impact of climatic change may provide insight into the future sustainability of wheat–maize double crop rotations in the NCP. [ABSTRACT FROM AUTHOR]

The pollen and spores of the Wuyun Formation (Danian, Early Paleocene) from Jiayin County, Heilongjiang Province, Northeast China, are studied in this paper. The Danian vegetation at Wuyun was composed of mixed temperate and subtropical broad-leaved forest, with an admixture of conifers. The climatic parameters, obtained by the Coexistence Approach based on the palynological and megafossil data, are Mean Annual Temperature of 14.8–16.8°C, Mean Annual Precipitation of 815.8–1,571.8 mm. Combining other climatic parameters in the Tertiary, we obtained the latitudinal temperature gradients: 0.24 in Paleocene, 0.1 in Eocene, 0.45 in Miocene and 0.55 in Pliocene, in the area of East Asia. All these values and modern latitudinal gradient of 0.7 suggest a climatic transition from Paleocene to today: the temperature at higher latitudes first increased then decreased gradually during last 65 Ma, while it changed slightly in lower latitudes. [ABSTRACT FROM AUTHOR]

In this paper, we quantified vegetation variations in the Qaidam Basin from 1982 to 2003 by using growing-season NDVI sequences, which were defined as the summation of monthly NDVI values from May to September, and were calculated pixel-by-pixel from a successive 8-km NDVI dataset. We adopt linear regressions to examine the trends in growing-season NDVI and the trends in climate (temperature, precipitation and sunshine duration) during this period in an attempt to depict their temporal and spatial variability. Our results indicate that climate in the Qaidam Basin has homogeneously warmed at a rate of about 0.6°C/decade during the study period, with significant trends in monthly mean temperatures in April-September. However, there were no statistically significant trends observed in precipitation and sunshine duration. We found positive growing-season NDVI trends in 31.6% of the vegetated lands in 1982-2003 and in 24.1% over the first half period, 1982-1992. In addition, few areas were shown to have negative trends during these periods. In 1993-2003, however, the percentage of land with a positive trend decreased to 13.1%, and the percentage of vegetated land with a negative trend increased to 10.2%. Growing-season NDVI trends show both temporal and spatial variability. Areas with negative trends are distributed mostly at lower elevations and near oasis boundaries, and areas with positive trends at higher elevations. Using correlation analyses we estimated the relationship between growing-season NDVI and the climatic factors with the consideration of duration and lagging effects. The results suggest that growing-season NDVI trends are more correlated to temperature increases in growing-season months when compared to variations in precipitation and sunshine duration; however increased precipitation amounts within May-August can also facilitate vegetation growth in some of this arid basin. However, we found no significant correlations between growing-season NDVI and temperature in the non-trend areas, which account for the majority of the vegetated land. We suggest that the variability in vegetation responses to the observed warming climates results from the differences in background thermal condition and moisture availability, which depend on elevation and other factors, such as hydrological conditions. [ABSTRACT FROM AUTHOR]

Slope stability models traditionally use simple indicators of root system structure and strength when vegetation is included as a factor. However, additional root system traits should be considered when managing vegetated slopes to avoid shallow substrate mass movement. Traits including root distribution, length, orientation and diameter are recognized as influencing soil fixation, but do not consider the spatial and temporal dimensions of roots within a system. Thick roots act like soil nails on slopes and the spatial position of these thick roots determines the arrangement of the associated thin roots. Thin roots act in tension during failure on slopes and if they traverse the potential shear zone, provide a major contribution in protecting against landslides. We discuss how root traits change depending on ontogeny and climate, how traits are affected by the local soil environment and the types of plastic responses expressed by the plant. How a landslide engineer can use this information when considering slope stability and management strategies is discussed, along with perspectives for future research. This review encompasses many ideas, data and concepts presented at the Second International Conference ‘Ground Bio- and Eco-engineering: The Use of Vegetation to Improve Slope Stability—ICGBE2’ held at Beijing, China, 14–18 July 2008. Several papers from this conference are published in this edition of Plant and Soil. [ABSTRACT FROM AUTHOR]

The ecological environment in the Tarim River Basin is extremely fragile. The ecological problems resulting from local economic development in this region have been a hot topic for the ecological scientists. There is a new trend to use information technologies to monitor the ecological environment dynamically by means of the modem information technologies. To meet the constant requirements of long-term monitoring of a region ecological environment, this paper focuses on the vegetation coverage and land desertification on the basis of the information technologies of remote sensing (RS), geographic positioning systems (GPS), geographic information systems (GIS), and data warehouse, applying the theory of the integrative spatial and attribute data, seamless integration of multi-source data. The ecological environment for the lower reaches of the Tarim River is analysed qualitatively and quantitatively. The investigated database is established and managed through multisource and multi-type massive data, which are collected from three periods of the remote sensing images and background data in 1999, 2002 and 2004, respectively. The methods of system classification, remote sensing interpretation, vegetation coverage, conversion models construction, and massive data built database are applied to analyse the data concerned during the dynamically monitoring the ecological environment in the Tarim River Basin. The results show that the vegetation coverage has increased gradually each year after the emergent water transportation project was started, whereas the desertification area has decreased, some sand areas have obviously retreated. The speed of improvement in the east part of the river has been higher than in the west. The ecological environment in the lower reaches of the Tarim River has tended to improve after the emergent water transportation project in the lower reaches of the Tarim River Basin. In conclusion, the emergent water delivery plays a decisive and significant role in promoting the ecological environment in this region. [ABSTRACT FROM AUTHOR]

This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071-2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within ±10% of observed flowering duration and ±15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances [ABSTRACT FROM AUTHOR]

Climate shows distinct variability on al spatial scales and the method of identifying areas with analogous climate is widely used. The technique is usually developed with some specific application in mind, human comfort, building types or, as in this case, agriculture. The paper addresses the topic as it applies in China, presenting first the method of basic climatic devisions and then explaining the threshold values used in agroclimatic classifications. Temperature is a major variable used in the classification, as is precipitation, but at the county level many other aspects are introduced. China also devised classifications for many specific crops, and rice is selected for special consideration. [ABSTRACT FROM AUTHOR]